Many pressure sensor assemblies of the prior art are improperly equipped to withstand extreme environments, such as harsh temperature environments, high vibration environments, and conductive and corrosive media environments.
Traditional wire bonded pressure sensors cannot be exposed to any of these environments without damage. As another example, sensors that utilize oil-filled technology, can be exposed to conductive and corrosive environments, however the operable temperature range of the sensor is significantly limited because of the presence of oil. As yet another example, leadless sensors, wherein the sensing elements are mounted upside down onto appropriately designed headers such that only the backside of the sensing element is exposed to the pressure media, are suitable for device operation in most extreme environments. In this particular embodiment, illustrated in FIG. 1, however, when exposed to a pressure media with high-dynamic thermal and flow conditions, the exposed micromachined diaphragm can experience uneven heating, and other flow-related stresses, because of the uneven shape of the exposed surface. Therefore, in combustion measuring and hypersonic measuring applications, the error associated with dynamic heat and flow related phenomenon becomes significant and limits the accuracy of traditional leadless sensors.
Because of the limitations presented in the above-mentioned prior art embodiments, there is a need for a pressure sensor assembly suitable for operation in extreme environments, including: (1) dynamic, ultra-high temperature heating environments, (2) light and heat flash environments, and (3) high-speed, flow-related environments.